Typewriting machine



July 16, 1940. H, HART 2,208,367 TYPEWRITING MACHINE Filled oct. 1, 195s 2 sheets-'sneer 1 July 16, 1940. H. J. HAR-r TYPEWRITING MACHINE Filed Ot; 1, 1938 2 Sheets-Sheet 2 INVENTOR H. cf Hcvr' mmv@ o ATTORNEYS Patented July 16, 1940-` UNITED STATES PATENT oFFlcE 2,208,367 p mEWRITING MACHINE Application October 1, 1938, Serial No. 232,869

30 Claims.

This invention relates to typewriting machines and more particularly to stops for arresting or limiting movement of typewriter carriages in letter-spacing or return directions and to mechanism for adjustably positioning such stops.

It is usual to provide cooperating stop elements on typewriter main frames and carriages for arresting or limiting movement of the carriages either for fixing the writing margins or for positioning the carriage for tabulating operations. The illustrative Aembodiment of the invention to be described comprisesv a typewriter including carriage-mounted stops arranged to cooperate with a stop on the frame for fixing a margin of the typed sheet and mechanism for adjustably positioning the carriage-mounted stops.' It will be understood, however, that the invention is adapted for more general application.

An object of the invention is to provide an improved form of adjustable stop for arresting or limiting letter-spacing or return movement of a typewriter carriage on the associated frame.

Another object is to provide mechanism cooperable with an adjustable stop for quickly and 5 25 4easily moving the stop along its support andautomatically setting it in adjusted position.

A further object is-to provide mechanism of the character referred to which is oi'- simple construction, easyto operate, and certain in its action in correctly positioning the stop.

' A 'further object is to provide a typewriter having a pair of adjustably mounted margin stops and mechanism for adjustably positioning the stops, the arrangementbeing such that the stops may be positioned by setting suitable control means, and moving the typewriter carriage to the desired margin positions. I

Other objects will become apparent from a reading of the following description, the Vappended claims, and the accompanying drawings, in

- which: v y

Figure 1 is a fragmentary front elevational View of a typewriter carriage, showing parts of mechanism embodying the invention;

'45 Figure 2 is a planview of an assembly of Asome ly in elevation, showing the'carriage end plates and right hand margin stop control means;

Figure 7 is a fragmentary `detail section taken on the line 1-1 of Figure 3, some parts being omitted for clarification.

Figure 8 is a 1fragmentary top planrview of parts as viewed when looking in the direction of the arrows 8-8 in ,Figure 3, and drawn on an enlarged scale;

Figure 9 is a fragmentary top view of parts as 10 viewed when looking in thedirection of the arrows 9-9 in Figure 3, and drawn on an enlarged scale; I

Figure 10 is a perspective view of a portion of a margin stop releasing bail; f

Figure 1l is a vertical section Vtaken on the line I I-I I of Figure 8;

Figure 12v is a distorted diagrammatic plan view l of a resilient stop-urging band and its mounting means;A 20

Figure 13 is a fragmentary end elevation as viewed when looking in the direction of the arrows I3-I3 in Figure 1, and showing an actuating lever in one position; v

Figure 14 is a view similar to Figure 13 but 25 showing the actuating lever in a different pomtion; and o I Figure 15 is a fragmentary view in end elevation showing a modication' including a spring for holding a bail actuating lever against acci- 30 dental displacement.

The drawings show only such of the usual parts of a typewriter as are necessary in order to make clear the manner of applying stopsand stopsetting mechanisms embodying the invention to 35 typewriters generally. A The known or usual parts .thus shown are ofV the form used in the Royal Standard typewriter' and include a main-frame- -mounted track A, a ma frame rear wall-part B,

and a carriage C havking a track l supported for 40 .letter-spacing and return movements on the track A by ball bearings 2. A platen or cylinder l is mounted in the usual manner between end plates I and 5 ,forming part of the carriage structure. A scale D is supported on the carriage as at 6--6 45 in the usual manner and is provided along its upper edge 'with-a work sheet and typing aligning scale 1, and along its bottom edge with a'carriage positioning ,scale. Central pointers 9 and.V Il formed on a ii/xed type bar guide E cooperate with the scale l' for assisting the operator to pomtion the carriage. A center stop Il of known kind is pivotallyvinounted at. at I2 on the frame wall B, and a line lock lever I3 is pivotally mounted as at I4 on the center stop Il in aknown manner. A if the carriage, being connected at its opposite ends to the end plates 4 and 5 as at I5 and I6 respectively'. L

In accordance with the disclosed embodiment of the invention, a stop is supported and normally locked in fixed position on the carriage for cooperation with the center stop Il tol arrest or limit movement of the carriage, the carriagemounted stop being urged constantly toward the center stop. Means are provided for quickly and easily unlocking the carriage mounted stop so as to permit it to be moved by the constant urge until it contacts the center stop, after which the carriage is moved to the desired margin position and the carriage-mounted stop then is locked to the carriage.

In the form shown, right and left hand Inargin stops, respectively designated G and G', are mounted on and for adjustment along a margin stop rod or bar H having transverse teeth I1 spaced along itsv upper face and beingsupported on and between the carriage end plates 4 and 5.

The left hand margin stop G includes a tubular body I8 formed with a lateral extension I9 which 'receives an adjustable abutment screw 20 adapted to cooperate with the center stop II in a manner to be described, a set screw 2I serving to hold the abutment screw 20 in adjusted position. A latch generally designated 22 is pivotally mounted as at 23 on the body I8, and is provided with a nose 24 adapted to t between adjacent teeth I1' on the margin stop bar H for releasably locking or holding the stop G in adjusted position on the bar I I. 'Ihe latch is formed with a horizontal arm 25 extendingL toward the center of the carriage, and a spring 26` held in' place by a stud 21 is interposed between the body I8 and the horizontal arm 25 for yieldably urging the latch nose 24 toward the teeth Hof therod H. The free end of the horizontal arm 25 is provided with a'roller 28 which functions for a purpose to be described later. Between the pivot 23 and the nose 24, the latch is provided with an upstanding nger piece 29 which serves as a means for manually releasing the latchwhen desired. Preferably, a companion finger piece 30 extends upwardly from the body I8, so that, when it is desired to release the latch 22, the two nger pieces 29 and 30 may be grasped between the thumb and for finger, and a squeezing action exerted. f

The construction of ythe right hand margin stop G is similar to that of the left hand stop G just described, the `only difference being that it is reversed as to right and left hand. Accordingly, nodetailed description of the right hand stop G is necessary. The reversely simirfor providing this urge is extremely compact and is fitted in among adjacent typewriter parts neatly and without protruding, and it therefore ydoes not present the appearance of an additional appendage or attachment. The margin stop urging means is adapted to exert alight but sure and substantially uniform or constant pull on the margin .stops irrespective of the relative positions of the stops. To this end the stop urging the spring will be under substantial tension.

tabular stop mounting assembly F is supported on means comprises a very long resilient band which is materially longer than the distance between the margin stops `G and G irrespective of the positions of the stops on the bar H. In the illustrative embodiment, the resilient band 5 comprises an elongated coil power spring I one end of which is connected to an ear 3| on thev body I8' of the stop G. From theear 3l the spring I extends to the left as at 32, and around a. sheave or roller 33 anti-frictonally journalled 10 on a bracket 34 secured to the end plate 4 by a screw 35. The spring then extends to the right as at 36 and around a sheave or roller 33' antifrictionally journalled on a bracket 34' secured tor the end plate 5 by a screw 35 so as to rotate. l5 about an axis inclined with respect to the axis of rotation of the roller 33. 'Ihence the spring extends to the left as at 31, and is connected to an ear 3| on the body I8 of the stop G. Thelength of the spring I is such that, when, the stops G and G are positioned near the center of the carriage, as indicated in dotted lines in Figure l, in which position ofthe stops the spring will be in its most contracted position,

25 To assure a light and uniform tension or con- -stant urge of the margin stops toward the center of the rod H, the coil spring 'band I is made extremely long. The length of the spring should be substantially greater than and preferably at 30 least twice as great asr the distance between the stops G and G' in any adjusted position of the s'tops. In the form shown the` spring is about three times as long as the length of either margin stop travel. The spring is made of such lengthbecause `it is important that `substantially the same urging force be exerted on the marginr stops G and G' irrespective of their positions on the bar H. In order that thespring function most efficiently in a construction embodying the 40 present invention, it should itself be of quite unusual formation. As applied to the Royal Standard eleven-inch typewriter, the contracted length of the preferred form of spring is about fifteen inches. When extended to its maximum length, 45 i. e., when the stops G and G are in the full line position shown in Figure 1, the spring is about twenty-nine and one-eighth inches long, and, when the stops are in the position shown in dotted lines in Figure 1, the length of the 50 spring is about twenty-two and five-eighth inches. The differences between the length of the spring for different adjusted positions of the margin stops are small as compared to the total length of the spring, so that a substantially 55 uniform pullis exerted on the margin stops regardless of their positions.

The spring preferably 'is formed of music wire, and, in the Royal Standard eleven-inch type-y writer, the wire used in forming the spring is 50 bility, and entire lack of tendency to crystallize.

Because of its unusual construction, the spring band I is quite sensitive to extension or stretching, and it therefore is desirable that the sheaves or rollers 33 and 33' be mounted for very free rota- 75 tion. Otherwise binding or frictional drag resulting in non-rotation of the sheaves would localize the stretching action of the spring to a small portion of the spring rather than permit the entire length of the spring to stretch or expand simultaneously. In order that the urge exerted by the spring be substantially uniform, it should of course be tensioned or stretched uniformly throughout its entire length. For example, referring to Figure 12, suppose that the margin stop ear 3l is moved toward the left, and suppose that the roller 33 should fail to rotate, due to a frictional drag. `'Ihe stretch 31 of the spring I would elongate to permit movement of the stop ear 3|, and the stretches 32 and 36 of the spring would notV elongate. Thus only a relatively small portion of the spring would be elongated, and consequently an unduly and undesired heavy pull would be imposed upon the stop ear 3l.' However,- if the rollers 33 and 33' are so mounted as to roll very freely, then any movement of either one of the margin stops will stretch not only the immediately adacent connected portion of the spring I, but will feed the spring around the rollers and stretch the spring uniformly throughout its entire length so as to provide a soft. easy,l expanding and contracting action, making it possible to move the stops away from each other easily, and also providing a soft, easy action tending to draw the stops toward each other when they are released or unlatched from the margin stop bar H.

To provide the desired free journalling of the rollers, they are mounted by anti-friction ball bearings, the bearings for the right' hand roller 33 being shown at 38' in Figure '1. Similar ballbearings, not shown, are provided for freely mounting the left hand roller 33. y In order to prevent accidental fouling or en-v tanglement of the spring I with adjacent parts, a housing 39 substantially enclosing the entire spring and mounted under the margin stop bar H is secured to the brackets 34 and 34' as at 48 and 40'. l

Control means conveniently located on the typewriter are provided for controlling the securing action of the latch 22 including releasing the latch so as to unlock the stop G from the bar H, permitting the spring I to draw the stop toward the right until arrested by the center stop Il. In the form shown, the control means includes a latch-releaser or baiLJ of generally inverted L shape having rearwardly extending arms 4I and 42 pivotally mounted as at 43-44 respectively on the tabular stop assembly F. 'Ihe bail includes a horizontally extending ledge 45 which overlies the path of the roller 28 on the stop G. v.Normally, the bail is in elevated position, as shown in Figures 3 and '1,` wherein the ledge 45 is above andout of contact with the roller 28. The pivotal mounting of the bail at 43 and 44 permits it to be moved downwardly to bring the ledge 45 into engagement with and to press on the roller 28 so as to raise the latch nose 24 to release or unlock the stop G from the stop bar H. When the latch is thus released, the spring I will pull the stop G to the light until the abutment screw 28 engages a buffer 4B which preferably is pivotally mounted on the center stop as at I4, a buffer spring 41 connected to the buffer element 48 and to the center stop serving to cushion the impact ofm the stop G. v

'I'he control means also includes releasable setposition-determining holding or -loclrlng means for maintaining the bail J set in its normal inactive position out of contact with the roller 28, for moving the bail downwardly to its operative position to press the roller 28 down, and for releasably locking or maintaining the bail set in its lower latch-releasing or operative position to maintain the latch nose free of engagement with the stop bar H. In the illustrative embodiment shown, the releasable holding or locking means comprises a cam and follower device connected through the bail J to the latch roller 28. A bail-actuating lever 48 is pivotally mounted as at |48 on the carriage end plate 4, and is provided with a holding part formed with an eccentric cam slot 48 which receives a cooperating holdingl part comprising a cam follower stud 58 which has threaded connection on a projection 5I extending from the arm 4l of the bail J. A finger piece 52 integral with the bail-actuating lever 48 provides for easy manual operation of the lever. Forward movement of the lever 48 and downward swinging movement of the bail are limited by engagement of the stud 58 "with the inner or closed end of the slot 49. Rearward movement of the lever 48 is limited by engagementl of the lever with a stop 53 eccentrically mounted on a stud 54 connected to the carriage end plate 4.

The lever 48 is formed adjacent the open end of the cam slot 48 with a recess or seat 55 upon which the stud 58 is adapted to rest in definite position to maintain the latch 45 of the bail above and out of contact with the latch roller 28. Proper seating of the stud 58 in the seat or recess 55 when the bail-actuating lever is in its rear position can be assured by adjusting the cam stop 53 so that the lever 48 will engage the stop when the seat 55 has come directly under the stud 58'. When the typewriter is in operation with the margin stop G in fixed position, the lever 48 will be in its retracted position in engagement with the stop 53, and the stud 58 will rest in the seat 55 so as positively to prevent the bail J from being accidentally lowered into contact with the roller 28.

'I'he shape of the cam slot 49 is such that, when the leven 48 is moved forwardly, the stud 58 will be moved down by its engagement with the upper side of the cam slot, thereby swinging the bail J downwardly so as to bring the ledge 45 of the bail into contact with the roller 28, pressing the roller downwardly and disengaging the latch from the toothed bar H. When the latch has thus been disengaged, the spring I will move the stop G to the right until arrested by the center stop in the manner already described. In order that the latch may be held or maintained in released position without its being necessary for the operator to hold the bailactuating lever 48 in its forward position, the upper side of the cam lslot 49 is formed with a recess or seat 56 which receives the stud 50 when the lever 48 has been moved forwardly to the position shown in Figure 14. 'Ihe depth of the recess 58. is such that, when the stud 58 is received in the recess, the bail J is locked down in its latch-releasing position. us the bail actuating and holding lever 48 will remain in ilxed position until manually released therefrom.

When it is desired to set the margin stop G in a position in which it will maintain a left hand margin equivalent to twenty letter spaces on the typed sheet, the bail-actuating lever 48 will be pulled forwardly so as to move the bail J downwardly and to cause the bail ledge to press upon the roller 28 and release the latch 22 in the manner alreadyhdescribed. The spring I then will draw the margin stop G to the right until arrested by the center stop. If the carriage vlever 48 will then be pushed rearwardly until it v operative engagement with the center stop. It isI apparent that, if the carriage is moved to the left during the typing of a line and is then returned to the right, engagement of the stop G with the center stop will arrest return movement of the carriage when the pointer 9 or I0 registers with the scale marking 20., thus iixing the left hand margin as desired. The engagement of the stud with the inner or closed end of the slot 49 of the lever ,48 limits the movement of the bail J to a position in which the bail cooperates with or presses upon the roller 28 so as to hold the latch nose 24 disengaged from the vbar teeth I1 without producing a frictional binding reaction between the bar H and the margin stop G or any part carried by the margin stop.

Similar control means is provided for releasing the latch 22 of the stop G' to permit setting of the stop G' for fixing the desired right hand margin. The control means associated with the stop Gincludes a bail J and a bail-actuating lever 48' similar to the bail J and actuating lever 48 already described, the only difference being that the bail J and bail-actuating lever 48' are reversed as to right and left hand'withrespect to the bail J and actuating leverv48. Accordingly, no detailed description of the bail J and actuating lever 48 is necessary. The reversely simf ilar parts of the bail J' and actuating lever 48' are designated by reference characters correspondingto those designating similar` or corresponding parts of the-bail J and lever 48, the

. tion of the lever 48 and bail J for releasing the latch 22. y

'Assuming thatit is desired to set the margin stop G so as to fix the lefthand margin at twenty letter spaces, and that it is desired to set the stop G so as to fix the Vright hand margin at seventy letter spaces, both levers 48 and 48' will be pulled forwardly, thereby releasing both latches 22 and 22C and permitting the springI to pull the vstops G and G' into engagement with the center stop. The carriage may thenfbe `moved untilthe pointer 9 or l0 registers with the marking ,20 on the scale 8, and the lever e8 is then pushed rearwardly to the position shown inl'igure 13, thus Aeecting locking of the margin stop G in adjusted position on the rod H. The carriage C may then be moved until the pointer 9 or l0 registers with the marking '70 on the scale 8 and the lever 48 pushedk rearwardly to the position shown in Figure 6 so as to effect locking of the stop G' to the bar H.

The two stops G and G' will thenbe set so as to maintain the proper left hand and righthand margins on the typed sheet.

Alternately, the stops may be set in the following manner. First, the levers 48 and 48 are pulled forwardly to release both latches 22 and 22'. The carriage is then moved to its extreme right hand position, which will effect positioning of the stop G at its extreme outer yor left hand position on the rod H. 'Ihe lever 48 is then moved rearwardly to effect locking of the stop G to the f rod H. The carriage is then moved to its extreme left hand position so as to locate the stop G' A adjacent the right hand end of the rod H, after which the lever 48 is returned to its rear position to eiect locking of the stop G to the rod H. Then the carriage is moved until the pointer 9 or IIJ registers with the scale mark 20, and the lever 48 is pulled forward to unlatch the stop G so as to'permit the spring I to pull the stop G to the right until arrested by the center stop. 'I'he lever 48 will then be returned to its rearward position so as to eiect locking of the stop G to the margin stop rod H. 'I'he carriage is then moved to the left until the pointer 9 or I0 registers with the scale mark 70.

the spring I to draw the stop G' to the left until Then the lever 48' is pulled' forward so as to unlatch the stop G and permit it engages the center stop. Finally, `the lever 48r in either its `forward position or its rear posif tion against accidental displacement.

It is apparent that new advantages and very desirable operating characteristics and results are obtained by using mechanism embodying the invention. In setting the adjustable stop or stops the operator need only manipulate conveniently located control means, and then shift the carriage to the desired location. It is not necessary for the operator to refer to special stop setting scales at the rear yof the typewriter, reference to the usual carriage-locating scale or a. previously typed or marked Ypart of the work sheet being sufficient. Consequently it is possible for the operator to set the stop or stops quickly, easily,

1. In a typewriter, a frame element; a carriage" "element mounted thereon for letter spacing and return movements; a iirst stop'device mounted on one of said elements; a second stop device cooperable with said first stop device and being adjustably mounted on the other of said elements for movement to selected positions thereon in the direction of said movement of the carriage; means urging said adjustably mounted stop towards said adjustably mounted stop in selected position on its mounting element against the action of said other stop; `means for releasably securing saidV y urging means; means lfor controlling the securing action of said securing means including a settable device adapted when moved to set position v vfor movement to selected positions thereon in the direction of said movement of the carriage; means urging said adjustably mounted stop towards said other stop; means forreleasably securing said adjustably mounted stop in selected position on its mounting element against the action of said urging means; and means including a lcam and follower device operatively connected to said securing means for releasing thelatter, said cam L being formed with a depression adapted to receive said follower when the securing means is in released position.

3. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing and return movements; a first stop device mounted on one of said elements; a second stop device cooperable with said first stop device and being adjustably mounted on the other of said elements for movement to selected positions thereon in the direction of said movement of the carriage; means urging said adjustably mounted stop towards said other stop; means for releasably securing said adjustably mounted stop in selected position on its mounting element against the action of said urging means; and means for controlling the securing action of said securing means including means for preventing accidental releasing of said securing means and for releasably maintaining the securing means in released position.

4. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing'and return movements; a first stop device mounted on one of said elements; a. second s top device cooperable with said rst stop device and being adjustably mounted on the other of said elements for movement to selectedpositions thereon in the direction of said movement of the carriage; means urging said adjustably mounted stop towards said other stop; means for releasably securing said adjustably mounted' stop in selected position on its mounting element against the action of said urging means; operating means including a cam and follower device operatively connected-to said securing means for releasing the latter, said cam beingv formed with a depres. sion adapted to receive saidfollower when the securing means is in released position; and means for normally maintaining said operatingmeans in inactive position to prevent. accidental releasing of said securingmeans.

5. In a typewriter, aframe elenlent; a carriage element mounted thereon for letter spacing and return movements; a rst -stop device mounted adjustably mountedon the other of said elements for movement to selected positions thereon in the direction of said movement of the carriage; means urging said adjustably mounted stop towards said other stop; alatch for releasably securing said adjustably mounted stop in selected position on its mounting element against the action of said means; a latch-releaser cooperable with saidlatch at any position of said adiustably mounted stop on its mounting element; and holding means releasably settable in xed position for maintaining said latch-releaser in latch-releasing position, said holding means being constructed and arranged to remain in said xed position until manually released therefrom.

6. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing and return movements; a first stop device mounted on one of said elements; a second stop device cooperable with said iirst stop device and being adjustably mounted on the other of said elements for movement to selected positions thereon in the direction of said 4movement of the carriage; means urging said adjustably mounted stop ytowards said other stop; a latch for releasably l securing said adjustably mounted stop in selected position on its mounting element againstthe action of said urging means; a latch-releaser cooperable with said latch at any position of said adjustably mounted stop on its mounting element; and means for operating said latch-releaser and for releasably maintaining it in latchreleasing position, said means including a holding device releasably settable in fixed position`for maintaining said latch-releaser in latch-releasing position, said holding device being constructed and arranged to remain in said xed position until manually released therefrom. g

7. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing and return movements; a center stop mounted on said frame element; a margin stop cooperable with said center stop and being adjustably mount ed on said carriage element for movement to selected positions thereon in the direction of said movement of the carriage; means urging said carriage-mounted stop towards said center stop; means for releasably securing said carriagemounted stop in selected position on said carriage; means for controlling the securing action of said securing means including a settable device adapted when moved to set position to maintain said securing means in released position;

the direction of said movement of the carriage; A"

elongated resilient means under tension connected to said margin stops respectively and urging both marginY stops toward said center stop; means mounting and so positioning said resilient means on theI element which mounts` the adjustable stop that the length of lsaid resilient means between its points of connection to said margin stops is I substantially greater than the distancebetween said margin stops in any adjusted positions thereof; and means for releasably securing said margin stops in selected positions on their mounting element.

9. In atypewriter, a frame element; a carriage element mounted thereon for letter spacing and returnmovement; a center stop 'mounted onone v of saidelements; a pair of spaced margin stops direction of said movement of the carriage; elonsaid margin stops respectively and urging both margin stops toward said center stop; means mounting and so positioning said resilient means on the element which mounts the adjustable stop that the length of said resilient means between its points of connection to said margin stops is at least twice as great as the distance between said margin stops in any adjusted positions thereof; and means for releasably securing said margin stops in selected lpositions on their mounting element.

10. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing vand return movement; a center stop on said frame element; a pair of spaced margin stops cooperable with said center stop and being adjustably mounted on said carriage element cfor movement to selected positions thereon in the direction of said movement of the carriage; 'elongated resilient means under tension connected to` said margin stops respectively and urging both margin stops toward said center stop; means mounting and so positioning said'resilient means on said carriage that the length of said resilient means between its pointsof connection to said margin-stops is substantially greater than the distance between said margin stops in any adjusted positions thereof; and meansV for releasably securing said margin stops in selected positions on their mounting element. f

11. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing and return movement; a center stop on said frame element; a pair of spaced margin stops cooperable with said center stop and being adjustably mounted on said carriage element for movement to selected positions thereon in the direction of said movement of the carriage; elongated resilient means under tension connected to said margin stops respectively and urging both margin stops toward said center stop; means mounting and so positioning said resilient means on said carriage that the length of said resilient means between its points of connection to said margin stops is at least twice as great as the distance between said margin stops in any adjusted positions thereof; and means for releasably securing said margin stops in selected positionson their mounting element.

i2. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing and return movement; a center stop mounted on one of said elements; a pair of spaced'margin stops cooperable with said center stop and being adjustably mounted on .the other of said elements for movement to selected positions thereon in the direction of said movement of the carriage; a pair of spaced rollers journalled at opposite ends of the element on which said margin stops are mounted; an elastic band connected at its opposite ends to said margin stops respectively and passing around said rollers; and means for releasably securing said margin stops in selected positions on their mounting element.

l3. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing and return movement; a center stop on said frame element; a pair of spaced margin stops cooperable with said center stop and being adjustably mounted on said carriage element for movement to selected positions thereon in the direction of said movement of the carriage; a pair of spaced rollers journalled at opposite ends of the carriage element; an elastic band connected at its oppolgated resilient means under tension connected to site ends to said margin stops respectively and passing around said rollers; and means for releasably securing said margin stops in selected positions on the carriage element.

14. In a typewriter, a frame; a carriage mounted thereon for letter spacing and return movement; a center stop on said frame; a toothed bar on said carriage; a pair of margin stops mounted on and for adjustment along said bar and being cooperable with said center stop; releasable latches associated with the margin stops respectively and engageable with said bar for retaining the margin stops against movement on the -bar; sheaves journalled on the carriage respectively adjacent opposite ends of said bar; and an elastic band connected to said margin stops and passing around said sheaves. f

l5. In a typewriter, a frame; a carriage mounted thereon for letter spacing and return movement; a center stop on saidframe; a toothed bar` onr said carriage; a pair of margin stops mounted on and for adjustment along said bar y and being cooperable withA said centerestop; re-

leasable latches associated with the marginstops respectively and engageable with said bar for retaining the margin stops against movement on the bar; sheaves anti-frictionally journalled on the carriage respectivelyadjacent opposite ends of said bar; and a long coil spring connected at its opposite ends respectively `to said margin stops and passing around said sheaves, said sheaves being so positioned on the carriage that the length of said spring between its points of connection to said margin stops is at least twice as great as the distance between said stops in any adjusted positions thereof.

16.` In a typewriter, a frame; a carriage mounted thereon for letter spacing and return movement and having right and left hand ends; a center stop on said frame; a margin stop bar on said carriage; a right margin stop mounted on and for adjustment along said bar between the right hand end of the carriage and the center stop; a left margin stop mounted on and for adjustment along said bar between the left-hand end of the carriageand the center stop; releasable means associated with the margin stops for holding them in adjusted position on said bar; right and left hand rrollers journalled on the carriage respectively adjacent the right and left hand ends thereof; and an elastic band connected at one end to said right margin stop,y then extending to the left and around said left hand roller, then extending to the right and around said right hand roller, and then extending to the left and being connected to said left margin stop.

1'1. In a typewriter, a frame; a. carriage mounted thereon for letter spacing and return movement and having right and left hand ends; a center stop on said frame; a margin stop bar on said carriage; a right margin stop mounted on and for adjustment along saidy bar between the right hand end of the carriage and the center stop; a left margin ystop mounted on and for adjustment along said bar between the left hand end of the carriage and the center stop; releasable means associated with the margin Stops for holding them in adjusted position on said bar; right and left hand. rollers journalled on the carriage respectively adjacent the right and left hand ends thereof; and a coil spring band connected at one end to said right margin stop, then extending to the left and around Said left hand roller, then extending to the right and around said right hand roller, and then extending to the left and being connected to said vleft j margin stop, said spring band being formed of a length of wire about five times as long as the total length of the band when the right and left margin stops are positioned respectively at the right and left hand limits of their travel on said rod.

18. In a typewriter, a frame; carriage mounted thereon for letter spacing and return movement and having right and left hand ends; a center stop on said framea margin stop bar on said carriage; a right margin stop mounted on and for adjustment along said bar between the right hand end of the carriage and the center stop; a left margin stop mounted on and for adjustment along said bar between the left hand stop, said rollers being mounted to rotate about axes mutually inclined with respect to each other whereby adjacent passing stretches of said band will be free from contact with each other.

19. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing and return movement; a center stop mounted on one of said elements; a pair of spaced margin stops cooperable with said center stop and being adjustably mounted on the ether of said elements for movement to selected positions thereon in the direction of said movement of the carriage; a pair of spaced rollers journalled at opposite ends of the element on which said margin stops are mounted; an elastic band connected at its opposite ends to said margin stops respectively and passing around said rollers; a housing for said band mounted on said margin-stop-mounting element and extending between said rollers; and means for releasably securing said margin stops in selected positions on their mounting element.

20. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing and return movement; a center stop mounted on one of said elements; a pair of spaced margin stops cooperable with said center stop and being adjustably mounted on the other of said elements for movement to selected positions thereon in the direction of said`movement of the carriage; an elastic band connected at its opposite ends to said margin stops respectively; spaced bandsupporting devices mounted respectively adjacent opposite ends of the margin-stop-supporting element and around which said band is passed and adapted -to move freely; and means for releasably seeming said margin stops in selected positions on their mounting element.

21. In a typewriter, a frame element; a carriage element mounted thereon for letter spacing and return movement; a center stop on said frame element; a pair of spaced margin stops cooperable with said center stop a'nd being adjustably mounted o n said carriage element for movement to selected positions thereon in the direction of said movement of the carriage; an elastic band connected at its opposite ends to said margin stops respectively; spaced band-supporting devices mounted respectively adjacent opposite ends of the carriage element and around which said band is passed and adapted to move freely; and means for releasably securing said margin stops in selected positions on the carriage element.

22. In a typewriter, a frame; a carriage mounted thereon for letter spacing and return movement and having right and-left hand ends; a center stop on said frame; a marginstop bar on said carriage; a right margin stop mounted on and for adjustment along said bar between the right hand end of the carriage and the center stop; a left margin stop mounted on and for adjustment along said bar between the lefthand end of the carriage and thev center stop; releasable means associated withv the margin stops for holding them in adjusted position on said bar; right and left hand band-supporting devices mounted on the carriage respectively adjacent the right and left hand ends thereof; and

an elastic band connected at one end to said right margin stop, then extending to the left and pass-A ing around said left hand band-supporting device for free movement relative thereto, then extending to the right and passing around said right hand band-supporting device for free movement relative thereto, and then extending'to the left'and being connected to said left margin stop. 23. In a typewriter, a frame element; a carriage element mounted thereon for letter-spacing and return movements; a center stop mounted on one of said elements; a margin stop cooperable .said center stop; means for releasably securing said margin stop in adjusted ,position on its mounting element against the action of said urg.- ing means; an operating member for releasing said securing means; and releasable holding means associated with said operating member for releasably xing the position of said member to maintain said securing means released.

24. In a typewriter, a frame; a carriage mounted thereon for letter-spacing and return move-.- ments, a center stop on said frame; a toothed margin stop bar on said carriage; a margin stop cooperable with said center stop and being mounted for adjusting movement longitudinally on said bar; a spring-pressed latch on said margin stop engageable with selected teeth on said bar for normally and releasably holding said margin stop in adjusted position on said bar; a vspring-powered device connected to said margin stop and urging it toward said center stop; an operating member pivoted on said carriage and extending longitudinally of and adjacent said bar and being movable to inactive position in which it has no effective operative connection with said latch and to operative position in which it operatively connects with the latch and holds the latch out of operative engagement with the toothed bar; and means for releasably maintaining the operating member in operative position, said means including two parts movable relatively one to the other and comprising a rst part fixed to the operating member and a coacting part mounted on the carriage and contacting said iirst part.

25. In a typewriter, a frame; a carriage mounted thereon for letter-spacing and return 4movements; a center stop on said frame; atoothed 4margin stop bar on said carriage; a. margin stop ed for adjusting movement lngitudinally on said bar; a spring-pressed latch on said margin stop engageable with selected teeth` on said bar for normally and releasably holding said margin stop in adjusted position on said bar; a spring-powered device connected to said margin stopl and urging it towardsaid` center stop; anoperating member pivoted on said carriage and extending longitudinally of and adjacent said bar and being movable to inactive position in which itv has no eiective operativeconnection with said latch and' to operative position in which it operatively connects with the latch and holds the latch out of operative engagement with the toothed bar; and means for releasably maintaining said operating member in inactive position including a part connected to the operating member and being movab'e therewith and a coacting part mounted on the carriage, one of said parts being formed with a seat and the other of said parts having a projecting portion adapted to be received by said seat when the ,operating member is in inactive position.

26. In a typewriter, a frame; a carriage mounted thereon for letter-spacing and return'movements; a center stop on said frame; a toothed margin stop bar on said carriage; a margin Vstop `cooperable with said center stop and being mounted for adjustingmovement longitudinally on said bar; a spring-pressed latch on said marginV stop engageable with selected teeth on said bar for normally and releasably holding said margin stop in adjusted position on said bar; a springpowered device connected to said margin stop and urging it toward said center stop; an operating member pivoted on said carriage and extending longitudinally of and adjacent said bar and being movable to inactive position in which it has no effective operative connection with said latch and to operative position in which it operatively connects with the latch and holds the latch out of operative engagement with the toothed bar; and means including a part connected to said operating member and a ccacting part mounted on said carriage for releasably holding said operating member selectively in said inactive and operative positions depending on which position it has been moved to. Y Y 27. In a typewriter, a frame; a carriage mounted thereonior letter-spacing and 'return movements; a center stop on said frame; a toothed margin stop bar on said carriage; a margin stop cooperable with said 'center stop and lbeing mounted for adjusting movement longitudinally A on said bar; a spring-pressed latch on said margin stop engageable with selected teeth on said bar for normally and releasably holding said margin stop in adjusted position on said bar;

a spring-powered device connected to said margin stop and urging it toward said center stop; an operating 'member' pivoted on said carriage and extending longitudinally of and adjacent said bar and being movable to inactive position in which it has no eiective operative connection with said latch and to operative position in which it operatively connects with the latch and holds the latch out of operative engagement with the ed thereon for letter-spacing and return movements; a center stop on said frame; a toothed margin stop bar on said carriage; a margin stop cooperable with said center stop and being mounted for adjusting movement longitudinally on said bar; a spring-pressed latch on said margin y stop engageable with selected teeth on said bar for normally and releasably holding said margin stop in adjusted position on said bar; a springpowered device connected to said margin stop and urging it toward said center stop; an operating member pivotedon said carriage and extending longitudinally of and adjacent said bar and being movable to inactive position in which it has no effective operative connection with said latch and to operative position in which it operatively connects with the latch and holds the latch out of operative engagement with the toothed bar; a pivoted iinger piece operatively connected to said operating member for moving the latter selectively to its said inactive and operative positions respectively; and a spring device contacting said iinger piece and yieldably holding it against accidental displacement.

29. In a typewriter, a frame; a carriage mount- Yed thereon for letter-spacing and return movements; a center stop on said frame; a toothed margin stop bar on said carriage; a margin stop cooperable `with said center 'stop and being mounted for'adjusting movement longitudinally on said bar; a spring-pressed latch on said margin stop engageable with selected teeth on said bar for normally and releasably holding said margin stop in adjusted position on said bar; a springpowered device connected to said margin stop and urging it toward said center stop; an operating member pivoted on said carriage and exposition, depending upon which position it has x last been moved to. V

30.y In a typewriter, a frame; a carriage mounted thereon for letter-spacing and return movements; a center stop on saidl frame; j a toothed margin stgp bar on said carriage; a margin stop cooperable with said center stop and being mounted for adjusting movement longitudinally on said bar; a spring-pressed latch on said margin stop engageable with selected teeth `on said bar for normally and releasably holding said margin stop-in adjusted position on saidbar; `an j actuating partVv on said latch adapted to be pressed for releasing the latch from tooth-engaging POSition; a power spring connected tosaid margin stop and urging it toward said center stop; an operating member mounted on said carriage and extending longitudinally of and adjacent said bar and being movable'to inactive positionin which it has no eiective operative connection with said actuating part, and to operative position in which it operatively connects with and presses said actuating part to move and hold the latch out of operative engagement with the toothed bar, whereby vsaid power spring is enabledto move said margin stop toward said center stop while said latch-actuating part Amaintains operative contactjwith said operating member; and limiting member is moved to the fixed position determined by said limiting means, said power spring will move said margin stop along the bar and against said center stop with the latch-actuating part moving along and in contact with but un- 5 l restrained by said operating member.

HENRY JOSEPH HART. 

